Currently, "information superhighway" and "multimedia" are probably the most often spoken and least often understood aspects of a coming revolution in data communication. Although issues specific to an information superhighway are beyond the scope of the present discussion, interactive multimedia systems are very much within the present scope.
An interactive multimedia system is broadly defined as a system capable of processing, storing, communicating and coordinating data pertaining to visual information, aural information and other information. Visual information is generally divided into still picture or graphics and full motion video or animation categories. In the vernacular of those involved in multimedia, such visual information is generically referred to as "video." Aural information is generally divided into speech and non-speech categories and is generically referred to as "voice." "Other information" is directed primarily to computer data, often organized in files and records, and perhaps constituting textual and graphical data. Such computer data are generally referred to as "data."
To date, multimedia has, for the most part, been limited to stand-alone computer systems or computer systems linked together in a local area network ("LAN"). While such isolated systems have proven popular and entertaining, the true value of multimedia will become apparent only when multimedia-capable wide area networks ("WANs") and protocol systems are developed, standardized and installed that permit truly interactive multimedia. Such multimedia systems will allow long distance communication of useful quantities of coordinated voice, video and data, providing, in effect, a multimedia extension to the voice-only services of the ubiquitous telephone network.
Fully interactive multimedia presentation of information obviously provides significant advantages in the business environment or otherwise. Consequently, a considerable amount of effort has been directed to delivering multimedia information to the end user. In connection therewith, many organizations are presently engaged in efforts to establish standards and recommendations for the interoperability of multimedia information throughout the communication networks.
For instance, the international community, through the agency of the International Telecommunication Union-Telecommunication sector ("ITU-T"), has been instrumental in the effort of producing guidelines and recommendations that allow multimedia systems from different manufacturers to interoperate with one another. One of the earliest recommendations from the ITU-T is the H.320 videoconferencing series of recommendations. The overview document, ITU-T Recommendation H.320-1993, entitled Narrow-Band Visual Telephone Systems and Terminal Equipment, and the related documents, define a set of recommendations that allow distant endpoints to connect together and exchange information over narrow-band channels (up to 1920 kbit/s) and ultimately provide video desktop conferencing and collaboration therebetween. A large number of systems have been developed employing this set of ITU-T recommendations. In conjunction therewith, a follow-up set of documents, ITU-T recommendations H.324-1995, entitled Terminal for Low Bitrate Multimedia Communication, were created to handle the distribution of multimedia information over slower communications channels (less than 64 Kbit/s). The aforementioned recommendations and related set of recommendations are incorporated herein by reference. Systems based on the aforementioned and related sets of recommendations are now operative and have achieved a substantial degree of market penetration.
One of the limitations with H.320 or H.324 compatible systems is that such systems are relegated to point-to-point connectivity. More specifically, H.320 or H.324 compatible systems support multimedia communication between two endpoints only. Obviously, it would be desirable in many applications for a source endpoint to communicate multimedia information to multiple destinations. For instance, a presentation by a corporate manager to employees located throughout the country on a new product line or on improvements to existing products would increase the delivery of pertinent information. The present systems requires a multimedia control unit ("MCU") to facilitate the communication from a single source to multiple endpoints. The MCUs allow each of the communications endpoints to establish a point-to-point connection with the MCU and the information is then replicated from the source to the multiple endpoints. For a small number of workstations the MCU approach provides a viable alternative; the MCU approach, however, becomes expensive and computationally infeasible as the number of workstations increases, even modestly. Thus, the use of the MCUs or a similar device in connection with the H.320 or H.324 compatible systems does not provide a viable solution for source to multiple endpoint communication.
Accordingly, what is needed in the art is a system and method that facilitates the communication of multimedia information between interchangeable source and multiple destination endpoints without substantially increasing the overhead of the system employing the same.